I'm not a huge expert of speakers, and I don't know if the two speakers can be compared to each other. What I think is, the Delta Pro seems to have a little more "traditional" sound - a little more in the bass range, with a dip around 500Hz, while the 3012HO has little less lows, and that mid emphasis around 550Hz which can be a more agressive sound (which might be great cutting through the mix).

I'd use them with the BGH25 tweeter.

Also there's the weight, I'd save 2kg with the 3012HO, which can be a lot when I have to carry the box for 500m!

The cab would be in charge in clubs, and bigger stages but always as a monitor, with FOH support.

What do your plans say? Are either driver listed in the plans? Bill is usually very good about putting updated drivers in the plans and how each driver effects the response. The Simplexx line are not horns, they are just correctly engineered and designed direct radiators.

I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

I know, it's hard to find out someones liking for his bass sound by reading and writing about it.
Maybe one more thing, that might be important, I'll use basses with low B string. As the tilt back version is slightly smaller, so has a little less lows, but still the 3012HO can have enough lows to sound good. Maybe some user with own experience can tell that!

Besides weight (and price ) is there any significant difference between the kappalite 3012HO and the delta pro 12-450A?

According to plans the 3012HO has a little higher Fs than advised, the 12-450A has a little more Vas than advised, but (for me) not significantly more or less.
...and the rest of the "important" parameters differenciate also little (for me):
Xmax: 3012HO 6.2mm > 12-450A 5.1mm
Fs: 12-450A 44Hz >3012HO 52Hz
Sensitivity: 3012HO 100.5dB >12-450A 99.8dB

Besides weight (and price ) is there any significant difference between the kappalite 3012HO and the delta pro 12-450A?

According to plans the 3012HO has a little higher Fs than advised, the 12-450A has a little more Vas than advised, but (for me) not significantly more or less.
...and the rest of the "important" parameters differenciate also little (for me):
Xmax: 3012HO 6.2mm > 12-450A 5.1mm
Fs: 12-450A 44Hz >3012HO 52Hz
Sensitivity: 3012HO 100.5dB >12-450A 99.8dB

Let's hope, I learn something! Thanks!

The reason you aren't getting an answer is that it would require someone to have built this particular cab (not that many out there yet as it's a newer design) and then used both speakers at some point in it. I just don't think you will find that example within the confines of the forum.

So, you have to make your decision on power handling and xmax vs. the charts of the speakers. Or, just flip a coin. Because any two players may prefer different speakers.

Bruce Weldy wrote:
The reason you aren't getting an answer is that it would require someone to have built this particular cab (not that many out there yet as it's a newer design) and then used both speakers at some point in it. I just don't think you will find that example within the confines of the forum.

So, you have to make your decision on power handling and xmax vs. the charts of the speakers. Or, just flip a coin. Because any two players may prefer different speakers.

Yeah, I thought, that it has a little chance, that someone tried both speakers in a Simplexx. That's why I thought, maybe someone can tell the difference between just the 2 speakers by themselves. But it can be, that without putting the speakers into a cab, you can't really compare them to each other.
Anyway, soon, I'll decide, and can tell my own experience with one of them!